Fire-box fob boilbbs



0. SMITH.

FIRE BOX FOR BOILERS. APPLICATION man JAN- I. ma.

1,319,184. Patented Oct. 21,1919

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UNITED STATES PATENT OFFICE.

DAVID. SMITH, or WELLESLETY, MASSACHUSETTS.

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To all whom it may concern:

Be it known that I, DAvID SMITH, a citizen of the United States, and resident of Wellesley, county of Norfolk, State of Messachusetts, have invented an Improvement in Fire-Boxes foryBoilers, of which the following description, in connection withthe accompanying drawing, is: a specification, like characters'on the drawing representing like parts.

This invention relates to improvements in fire boxes for fire tube boilers and the object thereof is to rovide a fire box which may be econon'iically constructed and which will be more efficient in the conservation of heat than those heretofore constructed.

More specifically the object of the invention is to provide a fire box in which the side and front walls and the bridge wall are constructed of water tubes so communicating and connected to the boiler .as to provide for the maintenance of a continuous upward circulation of water through said,

tubes to the boiler without permitting any dead or non-circulating space.

Anotherobject. of the invention is to produce a fire box construction in which the walls-are formed by water tubes so arranged and constructed as to rovide a limited flexibility which .will avoid straining of the 'boiler plate.

A further object of the invention is to provide-u substantially integral fire box structure in which all of the tubes forming the walls of the fire box are welded to one another.v

Other objects and'features of the inven tion will more fully appealfrom the follow ing description, the accompanying drawings and the annexed claims.

Thedrawings illustrate a preferred em bodimcnt of my invention as applied to a locomotive type of'boilor.

.In the drawings:

Figure 1 is a side elevation of a portion of the boiler and fire box, the inclosing wall of the fire box having been omitted,

Fig. 2 is a sectional view on lines 2, 2 Fig. 1 lookingitoward the fiuesheetof the boiler, and,

Fig. 3 1s a. front elevation showing in section the drums which extend forwardly from the boiler,

In the construction shown herein the boiler is of the usual fire tube type comprising the cylindrical boiler 1 with fire Specification of Letters latent.

Patented Oct. 21, 1919.

Application filed January 7, 1918. Serial No. 0,741.

tubes 2 extending therethrough and connected at their forward ends to the usual fine sheet 3. Drums' l, 5, and 6 preferably extend from the upper portion of the boiler, above the fire tubes, forwardly from the fire box and are supported at their outer or front endh by the bracket or metal wall which forms a housing for the fire box.

The fire box forming the subject matter of the present invention comprises a usual grate 7 which is inclined from its front end toward the rear and may be supported in any usual manner. The sides, front end,

" and the bridge wall of said fire box in the stantially rectangular in form and incloses the 'grate. The side members 10 and 11 of said manifold extend in parallelism with the side edges of the grate and preferably slightly below the top of said grate and are connected at their front ends by a transverse member 12 thus providing a structure which inclines downwardly from the front toward the rear end so that mud and silt will. settleand be carried by gravitation against'the flow of the water to the lower corners which are provided with mud valves 14'. i Theside walls of the,;'lire box are constructed of a series of vertical tubes 15, 16 which have inwardly curved upper ends 17 18 communicating respectively with the forwardly extending drums 5 and 6.

.The tubes 15, 16 preferably are welded,

electrically or autogenously at their lower ends to the side members 10, 11 of the manifold and at their upper ends to the drums 5, 6 respectively.

The forward end of the firebox structure is constructed of a plurality of series of tubes connected by headers in such a man: nor as to provide fire door apertures. As illustrated in Fig. 3 a series of water tubes 19 which preferably are welded to the transverse member 12 of themanifold extend u wardly to the walls of a header 20 which extends transversely across the front of the fire box and communicates at its ends with the fore.- most or corner tubes forming the side walls of thefir'e box. a

Another header 21 likewise communicat and are w elded at their upper cm s ing with the foremost or corner tubes of the said walls extends parallel to the header 20 and is spaced apart from it a sufiicient distance to provide am le height for a. fire door aperture. A plura 1ty of groups or series, preferably three of said groups, connect the headers 20 and 21, said groups being so disposed as to provide for the door apertures 25 and 26. These tubes, like the others, preferably are welded at their respective ends to the headers 20 and 21. Another series of tubes 27 extending upwardly from the header 21, and desirably converging, lead to a transverse superior header 28 which communicates at 1ts ends with the drums 5, 6. The header 8 may be curved downwardly beneath the surface of the drum 4 and if desired may be used toaid in supporting the latter.

The rear transverse member 13 of the header likewise is provided with a series of upwardly extending substantially vertical tubes 29 which connect at their upper. ends to a preferably are shaped header 30 which conforms to the contour of the barrel of the boiler and which communicates at its up er ends with the interior of the boiler. The header 30 is located in front of the end of the boiler and is so disposed as to protect the seam at the lower portion of the boiler which would otherwise be subject to the most intense heat of the fire box. The tra nsverse member 13 of the manifold, the upwardly extending tubes 29 and the curved header 30 form the bridge wall of the boiler.

It will be seen that the construction above described is substantially integral and so balanced that strains due to the ex ansion and contraction of the tubes will 0 set one ahother and prevent breakage or the spreading of seams thereby avoiding leakage. It will also be seen that by the elimination of the use of rivets and bolts ajnllch stronger construction is provided which will not be subject to the defects usually found in fire box constructions.

By thus constructing the fire box with manifolds connected to the lower portion of the boiler by tubes having a considerable length and connecting the upper ends of the side and end' tubes of the fire box to the drfims in the manner disclosed by welded joints a practically integral construction is provided in which a limited flexibility is permitted between the fire box and the boiler which will avoid strains upon the boiler plate and thereby increase the length of life of the boiler.

Furthermore the construction is such as to avoid all necessity of roviding apertures in the headers opposite t 1e ends of the tubes, which usually are provided to enable the insertion of the expanding tool for Securing the tubes to the headers. By thus limiting .brick or magnesia.

the necessity for these apertures the depressions or inequalities due to the insertion of plugs in such apertures is entirely avoided.

In the operation of the device the water from the boiler enters the tubes 8, 9 which communicate with the lower portion of the boiler and descending flows into the corners of the rectangular manifold which forms the bottom of t e fire box structure. It then flows upwardly toward the front of the fire box throu h the side members 10 and 11 of said mani old, at the same time rising in the vertical tubes forming the side walls of the fire box. When it rea ches the end of the fire box the water flows upwardly through the transverse member of the manifold through the tubes 19 into the header 20,- thence through the groups of tubes 22, 23, 24 into the header 21 from which it flows upwardly through the tubes 27 into the curved header 28 and is delivered by it to the forwardly extending drums 5 and 6 from which it returns directly to the barrel of the boiler. At the same time the water rising from the rear transverse member 13 of the manifold flows through the tubes 29 into the curved header 30 of the bridge wall. During this circulation the tendency of the water to rise as it is hcatedmaintains a constant and perfeet circulation. Inasmuch as the flow is comparatively gentle, dust and silt from the water drop into the manifold and naturally flow downwardly until they reach the lower transverse member of the manifold and can be drawn off by the usual mud valves 14. Feed water may be introduced in any convenient manner as for example throu h a suitable connection to a boss 31 at the Junetion of the horizontal and forward transverse members of the manifold.

The drums 4, 5, and (i in effect form the crown of the fire box, the space between the drum and the respective members 5 and 6 being filled in with. some suitable refractory material such as with fillings 32, 33 of lire This will prevent the fianicsfrmn the combustible material in the fire boxes from striking the drums at points above the water line.

It will. be understood that the construction disclosed herein is illustrative in character and that various changes may be,

made within the meaning and scope of the following claims.

Having thus described my invention what I claim as new and desire to secure by Letters Patient is:

1. ln combination with a fire tube boiler. havingfforwardly extending drums; a fire box construction comprising a grate, conduits extending downwardly from opposite, sides of said boiler, a i and end members inclosing said grate cornmunicating with said conduits, vertically extending tubes connecting with the side manifold having side members of said manifold and with said forwardly extending drums, a series of tubes extending u wardly from the rear member of said manifold a curved header connected to said tubes and communicating at its ends with said boiler, said curved header being so disposed as to protectthe seam of the boiler and with the vertical tubes to form the rear wall of the fire box. I

2, In combination with a fire tube boiler, a fire box constructioncomprising a bridge wall formed of a transverse bottom mamtfold communicating at its ends with the lower portion of the boiler, a seriesof'vertical tubes connected to said manifold, a downwardly curved header connected to the upper ends of said tubes and communicating with said boiler at a higher level than the connection of the manifold to said tube whereby a continuous upward circulation of water throu b said tubes will be maintained. 3. In com ination with a fire tube boiler, a fire box construction comprising a bri wall formed of a transverse bottom manl- -fold communicating at its ends with the lower portion of the boiler, a series of verti cal tubes welded to said manifoid, adownwardiy curved header welded to the upper ends of said tubes and communicating with said boiler at a higher level than connection of the manifold to said boiler whereby a continuous upward circulation of water through said tubes will be maintained.

4. In combination with a fire tube boiler, a fire box construction comprising a grate, a manifold connected to the lower portion of said boiler having side and transverse members inciosing said grate, tubes extendin-g upwardly from the forward corners of said manifold communicating with said 7 boiler, substantiall, horizontal transverse headers connecting aid corner tubes, and. a plurality of group of tubes connecting said transverse headers? said groups being'spaced apart to provide fire door apertures.

5. In combination with a fire tube boiler having forwardly extending drums, a fire box construction comprising a grate, a manifold connected to the lower portion of said boiler having side and transverse members inclosing said grate, tubes extendin upwardly from the forward corners o sald manifold communicating with said drums,

a pair of substantially horizontal transverse headers connecting said corner tubes, a plurality of groups of tubes connecting said headers, said groups being spaced apart to provide fire door apertures, and a series-of vertical tubes ct/rtmecting the, forward trans- 'fire. box construction comprising a gratd, a

manifold connected to the lower portion of said boiler havin side and transverse members inclosing said ate, tubes entendin upwardl from the f rward corners of sai, manifol connecting with said side drum's, a pair of horizontal transverse headers connecting said corner tubes, 'a plurality of groups of tubes connecting; said headers, said groups being spaced apart to provide fire door apertures, a series of vertical tubes connectingthe forward transverse member of said manifold to the lowermost transverse header, a header connecting said drums and a series of tubes connecting the upper transverse header with the drum connecting header.

7. In combination with a fire tube boiler, a fire box construction comprising a grate, a manifold connected to the lower portion of said boiler havi' side and transverse members inclosing sald grate, tubes extending upwardly from the forward corners of said manifold communicating with said boiler, a pair of horizontal transverse headers connecting said corner tubes and a plurality of groups of upwardly extending tubes connecting said transverse headers, said groups being spaced apart to provide fire door apertures, said upwardly extending tubes being joined to said manifold and said headers by welded'-3'oints.

8. In combination with a fire tube boiler having forwardly extending drums, a fire box construction comprising a grate, a manifold connected to the lower portion of said boiler havingside and transverse members inclosing said grate, 5 series of upwardly extending tubes connecting the side members of said manifold to said drums and joined to said manifold and said drums by welded joints, a air of transverse headers connecta ing the orward tubes of said series at the corners of said manifold, a plurality of groups of 'tubes connecting said headers, said groups being spaced apart to rovide fire door apertures and a seriesof to es connecting the forward transverse member of said manifold to the lowermost'header, all said tubes beingjpined to said manifold and to said headers bywelded joints.

In testimony whereof, I have signed my name to this specification.

v DAVID SMITH. 

